Gas turbine engines, such as those used to provide thrust for an aircraft, typically include a fan section and a core engine located downstream of the fan section. A nacelle may surround the fan section and the core engine and define an annular bypass duct between the nacelle and the core engine. During operation of an aircraft, air may be drawn into the gas turbine engine and accelerated by the fan section, and a fraction of the indrawn air may be routed through a path defined by the core engine where it may be compressed, combusted with fuel, and exhausted through an exhaust nozzle to provide primary forward thrust. The remaining indrawn air may pass through the bypass duct and exit through a nozzle to provide secondary forward thrust.
After touch down, a thrust reverser located at a downstream portion of the nacelle may be activated to provide reverse thrust which counteracts the forward thrust and assists in slowing down the aircraft. In general, the thrust reverser may consist of a translating sleeve, a plurality of blocker doors, and a plurality of thrust reverser cascades. When the thrust reverser is activated, the translating sleeve may slide axially downstream to a deployed position to expose the thrust reverser cascades, while the blocker doors may swing to a deployed position in which they may at least partially block airflow through the bypass duct, causing the air to be diverted through turning vanes of the thrust reverser cascades. The turning vanes of the thrust reverser cascades may turn the diverted airflow and generate a reverse thrust which counteracts the forward thrust.
Current technologies for manufacturing turning vanes of thrust reverser cascades may use composite materials which are fabricated by a hand lay-up process. For example, U.S. Patent Application Number 2013/0101406 describes thrust reverser cascades formed from compression molded composite materials composed of resin and fiber reinforcement. While effective, thrust reverser cascades fabricated by a hand lay-up process may be relatively expensive to manufacture and they may have limited shape complexity. Older manufacturing technologies for thrust reverser cascades have used aluminum-based turning vanes, but these types of vanes may not trade well from a weight perspective with other types of turning vanes. In addition, turning vanes with more flexible shapes may be desirable as they may provide increased reverse thrust within a given thrust reverser cascade length. As fan duct aerolines are often defined by the necessary thrust reverser cascade length required to achieve a specific reverse thrust, such reductions in in thrust reverser cascade lengths could lead to advantageous reductions in fan duct losses and external drag.
Clearly, there is a need for more cost-effective thrust reverser cascade constructions which provide more flexible turning vane shapes.